To alleviate the labor involved in milking, much of the milking process has been automated. Known milking machines have automated milk extraction and automatic cluster removal is available to remove milking equipment after milking. To fully automate the milking process, robotic milking systems have been developed. Typically, robotic milking machines aim to perform the tasks of recognizing and locating the cow teats; attaching the teat cups; together with, cleaning, pre-milking, milking and disinfecting the udder and teats of the cow. Due to the working environment and the wide variation in teat size, shape and orientation, the step of locating the teats has proved difficult. Inherent movement of the cow also lends to the difficulty in teat locating. As such, a variety of systems and methods have been attempted for locating the cow teats in robotic milking systems. Success rate of these system are typically dependent on the achievable accuracy and report rate as well as the bill of materials.
U.S. Pat. No. 6,227,142 entitled “Apparatus and Method for Recognizing and Determining the Position of a Part of an Animal,” the contents of which is incorporated herein by reference, describes capturing an image of an area illuminated with structured light, processing the image to identify a specific part of the animal, determining position of the animal part in three dimensions, and providing information for guiding an animal related device towards the determined position. Position of a single teat is determined by illuminating an identified teat with at least two projected lines, capturing an image of the lines and calculating a mean value of positions of the lines on the image. Optionally the line is a line of dots. Typically, the illumination is directed at an angle perpendicular to a longitudinal axis of a teat while the camera is positioned at an angle. The disclosure is specifically toward determining a single point position of a single animal part (a teat) per camera and does not provide three dimensional (3D) information regarding an orientation of the animal part.
U.S. Pat. No. 7,490,576 entitled “Time of Flight Teat Location System,” the contents of which is incorporated herein by reference, describes a teat location system for automated milking systems. The system has a light projection source and a special camera having a two dimensional array of pixels, each of which is capable of returning time of flight information as well as intensity to obtain 3D positioning of the teat.
U.S. Pat. No. 7,568,447 entitled “Improvements in or Related to Milking Machines,” the contents of which is incorporated herein by reference, describes a teat locating sensor for use in robotic milking machines and teat disinfection units. The captured image is processed by applying an edge detector to provide an edge image of the udder. A Hough transform is applied for detecting edges using semi-circles and near vertical forms. A feature detector then matches these to provide teat ends and teat sides and thus produces a teat location map. At least two cameras are required for locating the teats in 3D.
US Patent Application Publication No. US 2010/0186675 entitled “Implement for Automatically Milking a Dairy Animal,” the contents of which is incorporated herein by reference, describes an implement for automatically milking a dairy animal that includes a milking parlor, a sensor for observing a teat, and a milking robot for automatically attaching a teat cup to the teat. The sensor comprises a radiation source for emitting light, a receiver for receiving electromagnetic radiation reflected from the dairy animal, a lens, and sensor control unit. The sensor includes a matrix with a plurality of rows and a plurality of columns of receivers. The sensor control unit is designed to determine for each of the receivers a phase difference between the emitted and the reflected electromagnetic radiation in order to calculate the distance from the sensor to a plurality of points on the part to be observed of the dairy animal.